This invention relates generally to the control of degreasing apparatus; more specifically, it concerns the control of solvent vaporization in such apparatus in such manner as to effect substantial energy savings.
In solvent vapor degreasers, heat is introduced into liquid solvent to produce the vapor in a tank, the vapor condensing on the parts to be cleaned, and draining to a sump along with the soil. Solvent vapor which does not condense on the parts is liquified and either sprayed on the parts or directly returned to the sump, or both.
Parts are typically introduced to the tank from the top, with the tank cover open, and the cover is closed when the tank is not in use. In the past, it was thought necessary to heat the liquid solvent at the same rate, whether or not parts were being cleaned, to maintain the solvent sufficiently vaporized and recirculating, as described, so that parts or work could be degreased quickly and efficiently. Such constant heating, however, is wasteful of energy, but no way was known to substantially reduce energy consumption while maintaining the apparatus in vapor-filled condition for ready use, in the unusually advantageous manner as is now afforded by the present invention.